Front-drive and multidrive shuttle



Dec. 2, 1952 H. PELCE 2,619,988

FRONT-DRIVE AND MULTIDRIVE SHUTTLE Filed March 8, 1947 INVENTOH' Henri Hal 4' e ,4 TTQHN Y Patented Dec. 2, 1952 FRONT-DRIVE AND MULTIDRIVE SHUTTLE Henri Pelc, Paris, France, assignor to Socit dite: Saint Freres (Socit Anonyme), Paris,

France Application March 8, 1947, Serial No. 133,391 In France February 6, 1947 5 Claims.

Weaving cotton at very high speed on circular looms subjects the shuttles to extremely high forces which frequently are more than forty times the force of gravity.

It is essential that these shuttles be propelled under such conditions of balance that they will have no tendency to be hurled through the weaving shed, which might cause very serious casualties.

On the other hand, the stopping of such looms requires a substantial amount of time, owing to the speed of the loom. It is essential that the stopping of the looms should be effected as rapidly as possible by absorbing the kinetic energy of the shuttles. Moreover, the looms should be able to work backwards in the event any fault has occurred in weaving the cloth.

In accordance with the present invention, special shuttles and propelling members are provided which make it possible to attain very high speeds, to stop the loom almost instantaneously and to operate it in a reverse direction, when desired. They also make it possible to absorb the shocks resulting from sudden variations in movement.

The shuttles in accordance with the invention are of the type adapted to be rotated about the fixed axis of the loom and moved by a driving roller which exerts a driving action on the shuttle and, at the same time, revolves about its own ax1s.

A feature of the invention is that the propelling means of the shuttle is arranged in the forward portion of the shuttle and comprises a pair of idle or driven rollers, one of which is operative when the speed of the shuttle is being increased or remains uniform while the other is called into action when the speed is to be decreased and the suttle is impelled by its kinetic energy and thereby tends to overrun the driving means. The distance between the axes of the two idle rollers is such as to allow the shuttle to move as little as possible with respect to the driving roller. Since the crossing motion of the warp thread is synchronized with the driving roller, the shuttle cannot be permitted to move away from said driving roller without danger of its breaking through the warp thread.

Where a single shuttle is used, containing a large amount of weft thread, the shuttle in accordance with the invention is equipped with at least two propelling rollers, one of which is located adjacent the rear end of the shuttle while the other is provided at the front. Both of these rollers take part in the transmission of force while an idle roller located between the two propelling rollers performs the double function of acting to stop the shuttle and to propel it in the reverse direction.

A further feature of this invention is that preferably the rims of the driving rollers are covered with pneumatic tires filled with air under pressure.

Still other features and advantages of the invention will be apparent from the following description and claims in conjunction with the accompanying drawings, in which several embodiments are shown by way of example.

In the drawings:

Fig. 1 is a side view of a shuttle and associated driving means.

Fig. 2 is a plan view of the same shuttle.

Fig. 3 is a side view of a, modification.

Fig. 4 is a plan view of a multiple drive shuttle.

Fig. 5 is a radial section through one of the driving rollers on an enlarged scale.

Fig. 6 is a section similar to Fig. 5 but showing a modification.

Fig. '7 is a cross-section of the tire shown in Fig. 6.

Fig. 8 is a vertical section of the front and rear ends of the shuttle shown in Fig. 4.

As shown in Figs. 1 and 2, the shuttle I is driven by a driving roller 2 arranged between two idle, or driven, rollers 3 and 4 mounted on the forward end portion of the shuttle. The rollers have their axes directed radially with respect to the loom axis and lie in a horizontal plane. The driving roller 2 revolves about the axis of the loom and propels the shuttle by engagement with one or another of the driven rollers 3 and 4. At the same time, the rollers are rotatable about their own axes. When the driving roller 2 is in engagement with the roller 3, the roller 4 is located immediately behind the driving roller 2 and almost in engagement with it. The angular distance by which the shuttle I may overrun, and thereby get out of, its normal position is determined by the play between the retaining roller 4 and the driving roller 2.

This play, which is of the order of one centimeter, is trifling in comparison with the usual dimensions of circular looms. This small amount of play could not be obtained with a conventional back-drive shuttle.

Instead of having a driving roller located between two driven rollers, it is possible to have a driven roller on the shuttle located between two driving rollers. Thus, as shown in Fig. 3, a driven roller 3 provided at the forward end of the shuttle is located between a driving roller 2 and a reverse driving or stop roller which revolves about the axis of the loom, together with the driving roller 2. When the shuttle I, which normally is driven by the roller 2, gets ahead of that roller, it will come into engagement with the roller 5 and'thus will be retained in the position it must occupy to remain synchronized with the movement of the frames.

An advantage of the front drive is that stability and safety are considerably improved. Since the driving roller is at the forward end of the shuttle, the center of gravity of the shuttle is behind the .point of application of the force driving the shuttle. The driving force thus always tends to bring the center of gravity back to the line in which the force is applied. If the point of the application of the force acting on the shuttle is behind the center of gravity, the relationship is unstable since the force acting on the shuttle will tend to move the center of gravity away from the line of application.

Still. greater stability is obtained with the multi-drive shuttle illustrated in Fig. 4. This shuttle extends over an angular distance greater than 180, there being only a narrow sector 01-02 left between the front and rear ends of the shuttle for the crossing of the warp threads. At the forward end of the shuttle, a

driven roller 3 provided on the shuttle is disposed between a pair of spaced driving rollers 2 and 5 which are revolvable tog-ether about the axis of the loom. At the rear end of the shuttle, there is provided a driven roller 3a adapted to be engaged by a third driving roller 2a which is revolvable about the axis of the loom, together with driving rollers and 5.

In the case where two driving rollers are used simultaneously to drive the shuttle-in the same rotary direction, it is desirable for at least one of the rollers driven by these driving rollers to be resiliently connected to the shuttle so as to ensure a simultaneous contact of each pair of rollers. Figs. 4 and 8 show an example of such a resilient connection. The axle l5 of the driven roller 3a disposed at the rear end of the shuttle I is carried by a plate Hi which can slide forwardly and rearwardly with respect to the shuttlein a slide I! integral with the shuttle. A spring l8, fixed to the shuttle, resiliently thrusts this plate towards the rear. The strength and flexibility of the spring I 8 are chosen so that the contact of'the driving roller. 2a with. the driven, roller 3a is ensured at the same time as the: contact of the front driving roller 2 with the front driven roller 3, as long as these driving. rollers move in a forward direction. The

driving of the shuttle in a forward direction is thus effected by forces exerted on the front and on the rear ofthe shuttle, the total driving force being distributed between the sets of rollers. The driving roller 5 acts on the driven roller 3 to decelerate the shuttle, as, for example, when it is desired to stop the loom and also to move the shuttle in a rearward direction when reversal of the direction of operationlof the loom is desired.

One of the essential advantages of the arrangement shown in Fig. 4 is that, owing to the stiffness of the shuttle, a large portion of the centrifugal force developed is eliminated, since the shuttle is, as least to a large extent, self-abalancing. It is thereby possible to obtain rotational speeds which cannot, as a matter of practice, be obtained with short shuttles.

A further feature of the invention resides in the construction of the driving rollers. It has been found that the continual vibration resulting from the passing of the sheets of threads between the driving roller and the driven roller results in considerable wear. In accordance with the invention, this wear is substantially eliminated by providing the rim of the driving roller with a rubber tire containing air under pressure as in the pneumatic tires used on automobiles. With this construction, the vertical displacement of the shuttle and the vibrations due to the running on a sheet which is not entirely uniform are absorbed not by the material constituting the driving roller but by the air contained in the tire.

As illustrated in Fig. 5, one method of producing this special tire consists in molding a rubber ring having a hollow circular section and a diameter slightly less than that of the rim 1 of the driving roller 2 designed to receive the tire. The tire carries a tubular metal stem Bwhich is incorporated in the tire during molding. When the tire is mounted on the rim,

the stem 8 is inserted into a corresponding ap- In another construction, a rubber ring is molded with a U-shaped section, as indicated. at l I in Figs. 6 and 7. A sectionof this kind is easily molded. Rings l2 of high-adhesion rubber are molded on the rim of the driving roller 2. Thereafter, the ring H is mounted on the rim with its edges overlying the rings 12 and the three elements are vulcanized into a single unit. A valve l3 for the introduction of air is provided directly in the rim. In order. to obtain a still higher degree of strength and airtightness, additional rubber rims l4 may be molded on the rim so as to overlie and embrace the edges of the ring H. The treads of therollers are preferably smooth.

It will be understood that the embodiments illustrated in the drawings are shown only by way of example and that the invention is not lim-' ited to these particular embodiments.

What I claim as my invention and desire to secure by Letters Patent is:

1. In a circular loom, the combination of a shuttle adapted to be rotated about the fixed axis of the loom, two driven. rollers assembled on the shuttle, one to the fore,- one to the rear, and three driving rollers revolvable together about the axis of the loom, said rollers having smooth treads and having their axes directed radially in a horizontal plane, two of said driving rollers being placed behind the two driven rollers, and in contact with said driven rollers during the weaving, and the third being placed at a little distance ahead of the front driven roller.

2. In a circular loom, the combination of a shuttle adapted to be rotated in a circular path about the fixed axis of the loom, said shuttle extending around a major portion of the oil'- cumference of said loom, only a free space remaining between its ends for the crossing of the threads, two driven rollers assembled on the shuttle, near its respective ends, the circumferential distance between said rollers across cumferential length of said circular path, and two driving rollers revolvable together about the center of said circumference and placed respectively behind the two rollers assembled on the shuttle so as to exert a thrust on said two driven rollers respectively, said rollers having smooth treads and having their axes directed radially in a horizontal plane.

3. In a circular loom, the combination of a shuttle adapted to be rotated about the fixed axis of the loom, said shuttle extending around a major portion of the circumference of said loom, only a free space remaining between its ends for the crossing of the threads, two driven rollers assembled on the shuttle, near its respective ends, and two driving rollers revolvable together about the center of said circumference and placed respectively behind the two rollers assembled on the shuttle so as to exert a thrust on said two driven rollers respectively, said rollers having smooth treads and having their axes directed radially in a horizontal plane, at least one of the driven rollers assembled on the shuttle being connected to said shuttle resiliently in the direction of movement of the shuttle.

4. In a circular loom, a shuttle adapted to be rotated about the fixed axis of the loom, said shuttle extending around a major portion of the circumference of said loom with only a small gap between its ends for the crossing of the threads, a bobbin extending a major portion of the circumferential length of said shuttle, driven rollers assembled on the shuttle near its respective ends and driving rollers revolvable about the axis of the loom and engaging said driven rollers.

5. In a circular loom, a shuttle adapted to be rotated about the fixed axis of the loom, said shuttle extending around a major portion of the circumference of said loom with only a small gap between its ends for the crossing of the threads, said shuttle being of substantially uniform cross section throughout a major portion of its length, with taper-ed end portions, and being substantially balanced dynamic-ally in rotation about said axis, a plurality of driven rollers provided on the shuttle and cooperating driving rollers revolvable about the axis of the loom and engaging said driven rollers.

HENRI PELCE'L REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

